Attachment to dental engines.



INI/ENTO? ENTE@ STATE@ PATENT FFlME.

ALEXANDER SVED, OF NEW YORK, N. Y.

ATTACHMENT T0 DENTAL ENGINES.

Application led August 5, 1916.

To all whom t may concern:

Be it lknown that I, ALEXANDER SvED, a citizen of the United States, residing at New York city, in the county of Bronx and State of New York, have invented a new and useful Improvement in Attachments to Dental Engines, of which the following is a specification.

My invention relates to improvements in handpieces for dental engines patented by- I-Iarper, 651,922, June 19, 1900 in which a 25 or 300 bend is introduced as an improvement in right angle hand pieces; and the object of my improvement is to provide an instrument for dental students and practitioners, which will partly dispense with the extensive use of mouth mirrors and which will enable dental operators to prepare distal, buccal and lingual cavities'in molar, cuspd and bicuspid teeth with greater ease.

I attain this object by introducing a movable head in the so-called contra angle, which may be fixed infour positions with respect to the axis of the instrument. This improvement will enable the operator to reach many difficult points in the mouth without assuming unnatural positions and his hand as well as the head of the instrument will be out of his line of vision. In the accompanying drawing- Figure 1 is a view of the entire instrument, the improved portion being shown in longitudinal section; Fig. 2, a transverse section on line 2 2, Fig. 1; Fig. 3, a transverse section on line 3-8, Fig. 1, and Fig. 1 is also a transverse section of the instrument on line 4 4, Fig. 1. Fig. 5 is the transverse section of the instrument on line 5 5 Fig. 1.

Similar numerals refer to similar parts throughout the several views. j

The head 1 is screwed on the upper end of hollow shaft 2 the collar on which insures sufficient locking to prevent loosening of head 1. The'lower end of hollow shaft 2 is threaded to receive the selflocking nut 5, which holds .the hollow shaft loosely in jacket 3, so that the said hollow shaft can be turned in the said jacket by means of head 1.l

Sleeve L1, forms part of the outer shell of the instrument and it serves also to lock hollow shaft 2, and jacket 3, together. rIhis is accomplished by drawing the square section of sleeve 1, over the similar sections of hol- Speeication of Letters Patent.

Patented Feb. 20, 1917.

Serial No. 113,276.

low shaft 2 and jacket 3. The parts are proportioned so, that when sleeve 4L is held in position by the helical spring 6, the jacket and hollow shaft are locked together, thus no motion of the head will be possible. If however the sleeve is drawn back against the spring, the hollow shaft will be disengaged and the. head can be turned to the required position, where it may be fixed by the sleeve upon releasing the spring. The head can be fixed in four positions only as determined by the square sections of the various parts.

Jacket 3 is screwed into body 7. The collar on the jacket serves for locking these parts together and to form a base for spring 6.

My invention is intended to be an improvement of the invention of Harper #651,922 June 19, 1900, which consists of a fixed right angle head and a bent body, where consequently the angle made by the bur and the axis of the body of the instrument is a fixed obtuse angle. The introduction of a movable head will allow of changing this obtuse angle to an acute angle by turning the head 1800, and when the head is turned 90o from the position shown by the drawing, the bur will make 90o with the long axis of the body.

The arrangement of the parts is such, that any force which may come on the head, will be transmitted by hollow shaft 2 and jacket 3, to body 7 without stressing shaft S. Thus no v additional energy will be required to overcome the force of friction,

Awhich would be produced if the shaft S is stressed.

The head 1, shaft 8, gear 9, gear 10, body 7 and parts within the body form no part of my invention. I am aware that prior to my invention instruments with ixed head and bent body were made, therefore I do not claim such a combination; but

I claim:

A handpiece for dental engines provided with, (a) a hollow shaft having a square section to which the head is secured and which receives the driving shaft of the instrument, (b) a jacket having a square section receiving the saidmhollow shaft in which the latter may be rotated, and which is attached to a bent body, (o) a sleeve having an internal square section sliding over the square sections of the said holloW shaft and that the accidental unlocking of the said jacket, thus releasing or locking the said parts, will be impossible, all substantially as parts, (d) a nut screwed on the end of the described.

hollow shaft to hold the said hollow shaft ALEXANDER SVED. in the said j acket7 (e) a helical spring hold- Witnesses:

ing the said sleeve in position to lock the ISADORE SCHER,

said hollow shaft and jacket together, so EUGENE SPITZER.

Copies of this patent may be obtained for ve cents each, by addressing the "Commissioner of Patents, Washington, I). C. 

